Fixture for a table saw

ABSTRACT

A self-adjusting accessory for a table saw that includes a guide for sliding in the guide groove of the work supporting table of a table saw and which is biased against the edge of the guide groove which is closest to the cutting blade. The guide bar is used in conjunction with the plurality of table saw fixtures such as a miter gauge, an alignment gauge and a stop gauge. The alignment gauge also forms part of apparatus for carrying out a method of verifying the straightness of the arbor for the cutting blade, the alignment of the arbor relative to the guide groove of the work supporting table and the flatness of the cutting blade. The invention also includes an apparatus for adjusting the alignment of the arbor relative to the guide groove of the work supporting table.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §119(e) of priorU.S. application Ser. No. 09/055,896, filed Apr. 6, 1998, now U.S. Pat.No. 6,195,905; which is a division of U.S. application Ser. No.08/459,747, filed Jun. 2, 1995, now U.S. Pat. No. 5,735,054; which arehereby incorporated by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention has been created without the sponsorship or funding ofany federally sponsored research or development program.

BACKGROUND OF THE INVENTION

The present invention relates generally to a table saw fixture andparticularly to a fixture and fixture combinations which provideaccurate alignment to enable square cuts to be made on a workpiece. Theinvention also relates to a method of verifying the alignment of thearbor for the cutting blade, relative to the guide groove in the worksupporting table of a table saw, as well as a method of and apparatusfor adjusting the alignment of the arbor relative to the guide groove.

The modern table saw has a work supporting table which is provided witha slot and at least one guide groove in the upper surface of the tablewhich is parallel with the slot. A circular cutting blade is mounted onan arbor which is rotatably mounted on a cradle which is connected tothe table so that the blade extends through the slot in the table. Thecradle is mounted on the table so that it can be raised or lowered andso that it can be rotated about a front to back horizontal axis. Thisenables the operator to adjust the amount of cutting height of the sawand the cutting angle of the saw, relative to the upper surface of thework supporting table.

The arbor supporting cradle in most modern table saws is pivotallymounted between a pair of trunnions. One trunnion is fastened to thebottom surface of the supporting table at the front end of the tablesaw. The other trunnion is fastened to the bottom surface of thesupporting table at the rear end of the saw. The rear trunnion isfastened by bolts which extend through oversize holes in the reartrunnion. This enables the rear trunnion to be moved laterally a smallamount, relative to the front trunnion, to correct for a possiblemisalignment of the arbor relative to the guide groove in the worksupporting table. It is essential that the arbor be at a right angle tothe guide groove so that the cutting blade is parallel with the guidegroove of the supporting table. If the cutting blade is not parallelwith the guide groove, the bolts which fasten the rear trunnion to thesupporting table are loosened and the rear trunnion is forced into anadjusted position, for example by striking the trunnion with a hammer tomove the rear trunnion laterally and to change the alignment of thecutting blade relative to the guide groove. This represents a crude andimprecise adjusting feature. It is extremely difficult to align thecutting blade relative to the guide groove with any degree of accuracyby the use of hammer blows. Also, even if an accurate alignment of thecutting blade is achieved, the achieved correct alignment can be lostwhen the bolts which hold the rear trunnion to the table are tightened.

The accurate cutting of a workpiece can be affected by factors otherthan the alignment of the cutting blade to the guide groove of thesupporting table. These other factors include a cutting blade which maynot be perfectly flat, an arbor which may not be perfectly straight anda guide groove which does not have a uniform width or is too wide forthe guide bar of a fixture which is used for a cutting operation.

Verification devices have been developed for checking the alignment ofthe cutting blade with the guide groove of a table saw and for theflatness of the cutting blade. A typical verification device includes anelogated guide bar for slidable mouting in the guide slot of the worksupporting table, a cross bar which is connected to the guide bar forsupporting a gauge such as a feeler gauge which has a dial face, a dialand a plunger which is mounted of the gauge for axial movement relativeto dial face and which is operatively connected to the dial. Althoughthe gauge portion of the verification device is a very accurateinstrument, inaccurate readings are obtained from the gauge due to aless than precise fit of the guide bar portion of the verificationdevice within the guide groove and the lack uniformity in the width ofthe groove. One prior art specification device utilizes a split barwhich can be adjusted to fit into the guide slot by screws which arethreaded into the bar. However, the device must be readjusted foranother application. Also, prior art verification device which employ adial gauge are limited in the ways that they can be used, due to themanner in which the dial gauge is mounted on the cross bar.

Inaccurate cutting of a workpiece occurs even if the longitudinal axisof the arbor is properly aligned with the guide groove and the guide barof the fixture, such as a miter gauge, fits perfectly in a perfectlyuniform guide groove. Inaccurate cuttings can occur if the arbor is notstraight or if the cutting blade is not flat. If the arbor is straightand the guide bar of the fixture fits perfectly in the guide groove ofthe table saw, a misalignment of the arbor relative to the guide grooveor a warp in the cutting blade can be detected by existing verificationdevices. However, there is no effective way to determine thestraightness of the arbor without removing the arbor from the table sawor of making a proper adjustment of the arbor if one or more othervariables which affect alignment are present. If there are errors orflaws in two or more variables, it is very difficult to verify andisolate the flaws and to correct them.

Proper alignment of the cutting blade and fixtures is particularlycritical when the table saw is used for cutting very thin strips from aworkpiece, i.e. for cutting veneer strips. For such thin pieces,uniformity of thickness is critical. Cutting accuracy must be maintainedwith low tolerance for error. Also, there is a lower limit to the widthof strip which can be cut on a table saw by using conventional equipmentand methods. Still further, precise cuts are extremely difficult toobtain on a conventional table saw, using conventional fixtures. Theseand other difficulties experienced with the prior art table saws, tablesaw fixtures, and method of using the fixtures with table saws have beenobviated by the present invention.

It is, therefore, a principal object of the invention to provide averification apparatus for checking all variables in a conventionaltable saw which contribute to alignment errors between the cutting bladeand guide groove in the work supporting table of the table saw.

Another object of the invention is the provision of a method of checkingand measuring all variables in a conventional table saw which contributeto alignment errors between the cutting blade and the guide groove inthe work supporting table of the table saw.

A further object of the invention is the provision of an apparatus forand a method of positively and precisely aligning the arbor of a tablesaw relative to the guide groove in the work supporting table of thetable saw.

It is another object of the invention to provide a self-adjusting guidebar for sliding in the guide groove of a table saw for use with aplurality of saw fixtures and which maintains a constant and preciserelationship between the fixture and the cutting blade of the table saw.

A still further object of the invention is the provision of an alignmentgauge which has improved precision and versatility.

It is a further object of the invention to provide a locating gauge foruse in a table saw to enable narrow pieces to be cut from a workpiecewith improved accuracy and uniformity.

With these and other objects in view, as will be apparent to thoseskilled in the art, the invention resides in the combination of partsand steps set forth in the specification and covered by the claimsappended hereto.

SUMMARY OF THE INVENTION

The present invention includes an accessory for a table saw which has afixture which is connected to a self-adjusting guide mechanism forsliding in the guide groove in the upper surface of the work supportingtable of a table saw. The guide mechanism includes an elongated bar forsliding in the guide groove and at least two spaced yieldablecompensators which protrude from one vertical side surface of the barfor engaging one of the side surfaces of the guide groove of thesupporting table to maintain the opposite vertical side surface at thebar snugly against the opposite side surface of the guide groove. Morespecifically, each compensator includes a horizontal bore in the guidebar, a plunger for extending beyond one of the vertical side surfaces ofthe bar, a stop for limiting the amount by which the compensatorsprotrude beyond the side surface of the bar, and means for biasing theplunger against the stop. In one form of the invention, the fixture is amiter gauge. In a second form of the invention, the fixture is analignment gauge. In a still further form of the invention, the fixtureis a work locating gauge for cutting narrow strips from a workpiece. Thepresent invention also includes a method of verifying the straightnessof the arbor on which the cutting blade is mounted in the axialalignment of the arbor relative to the guide groove of the table saw.The straightness of the arbor in a table saw is preferably verified byapplying a reference plate which has a flat reference surface and a borewhich is transverse to the reference surface onto the arbor of a tablesaw so that the reference plate rests against the conventional cuttingblade locating stop of the arbor and the reference surface of thereference plate faces the guide groove of the table saw. Thestraightness of the arbor can be checked by a saw blade which is notnecessarily perfectly flat as long as the saw blade remains stationary.An alignment gauge is applied to the guide groove of the table saw. Thealignment gauge has an elongated guide bar for sliding in the guidegroove and a cross bar which supports a dial gauge and a feeler rodwhich is slidingly mounted relative to the dial gauge for movementtoward and away from the reference surface of the reference plate. Thealignment gauge is positioned so that the feeler rod engages the surfaceof a reference plate and the arbor is rotated to a plurality of angularpositions relative to the reference plate while maintaining thereference plate in a fixed position so that gauge readings can be takenat each of the angular positions. The right angle alignment of the arborcan be verified by applying the reference plate to the arbor so theplate extends through the slot for the cutting blade in the worksupporting table and above the upper surface of the table. The alignmentgauge is applied to the saw so that the guide bar of the gauge isslidably mounted in the guide groove and the feeler rod of the dialgauge extends to the reference surface of the reference plate. Thealignment gauge is positioned at a first point in the guide groove ofthe work supporting table so that the feeler rod engages a first pointat the front of the reference surface of the reference plate to obtain afirst gauge reading. The dial gauge is then positioned at a second pointalong the guide groove of the work supporting table saw so that thefeeler rod engages a second point at the rear of the reference surfaceof the reference plate to obtain a second gauge reading. The first andsecond readings are compared to determine if the arbor is at a rightangle to the guide groove. In addition to the reference plate, theapparatus for verifying the straightness of the arbor in a table sawalso includes a cap which is fixed to the free end of the arbor and acompression spring for mounting on the arbor between the reference plateand the cap to bias the reference plate against the stop on the arbor.This enables the arbor to be rotated relative to the reference plate andstopped at periodic increments of rotation so that a gauge reading canbe taken each time that the arbor stopped.

The present invention also includes a method of and an apparatus forchanging the alignment of the arbor if it is determined by theverification apparatus and method that the arbor of the presentinvention is not at a right angle to the guide groove of the supportingtable. The alignment apparatus and method of the present invention areapplicable to table saws in which the arbor is supported for rotation ona cradle which is, in turn, pivotally mounted between a pair oftrunnions wherein each trunnion has a pair of flanges which enable thetrunnion to be connected to the work supporting table by a pair ofbolts. Each flange has a vertical aperture which is vertically alignedwith a threaded vertical aperture in the work supporting table. Thealignment apparatus of the present invention includes a pair of L-shapedbrackets having a vertical leg and a horizontal leg. The vertical leghas a threaded aperture for receiving an adjusting screw. The horizontalleg has a vertical hole for receiving a bolt. Realignment of the arboris accomplished by removing the bolts, one at a time, which connect oneof the trunnions to the work supporting table of the table saw andpositioning the brackets at opposite sides of the trunnion so that thehorizontal leg portions of the brackets are below the flanges of thetrunnion and the hole in the horizontal leg of each bracket isvertically aligned with the aperture in the flange with which thehorizontal leg is engaged. A bolt is extended through the hole in thehorizontal leg portion of each bracket and the aperture of thecorresponding flange of the trunnion. The bolts are threaded into thethreaded apertures in the table to support the L-shaped brackets and thetrunnion but not tightened so that the trunnion is loosely connected tothe supporting table and the trunnion is free to be moved laterally aslight amount. The trunnion is moved laterally to change the alignmentof the arbor by rotating one of the adjusting screws until it engagesthe end edge of the flange. Additional rotation of the adjusting screwcauses the trunnion to move laterally toward the other L-shaped bracketuntil the arbor is at a right angle to the guide groove of the table sawas verified by the verification apparatus of the present invention. Theother adjusting screw is then advanced until it touches the edge of theopposite flange of the trunnion so that the trunnion is essentiallylocked in its correct position with respect to the right angle alignmentof the arbor with the guide groove of the work supporting table. Eachadjusting screw is provided with a lock nut to make sure that thetrunnion remains in the correct set position. The trunnion bolts canthen be tightened to secure the trunnion in the correct adjustedposition.

BRIEF DESCRIPTION OF THE DRAWINGS

The character of the invention, however, may be best understood byreference to one of its structural forms, as illustrated by theaccompanying drawings, in which:

FIG. 1 is a perspective view of a miter gauge embodying theself-adjusting accessory principle of the present invention and shownapplied to the supporting table of a conventional table saw;

FIG. 2 is a top plan view of the miter gauge;

FIG. 3 is a vertical cross-sectional view of the miter gauge, takenalong the line III—III of FIG. 2 and looking in the direction of thearrows;

FIG. 4 is a vertical cross-sectional view of the miter gauge, takenalong the line IV-IV of FIG. 2 and looking in the direction of thearrows;

FIG. 5 is a perspective view of an alignment gauge embodying theself-adjusting accessory principle of the present invention and shownapplied to the supporting table of a conventional table saw;

FIG. 6 is a top plan view of the alignment gauge;

FIG. 7 is a side elevational view of the alignment gauge, looking in thedirection of arrow VII of FIG. 6;

FIG. 8 is an end view of the alignment gauge, looking in the directionof arrow 8 of FIG. 7;

FIG. 9 is a side elevation view of apparatus which is used for verifyingthe straightness of the arbor of the table saw which includes thealignment gauge of FIGS. 6-8;

FIG. 10 is an end view the cap portion of the apparatus for verifyingthe arbor straightness;

FIG. 11 is a face view of a cutting blade for a table saw;

FIG. 12 is a face view of the reference surface of a reference platewhich forms part of the verification apparatus of FIG. 9;

FIG. 13 is a rear elevation view of apparatus for aligning the arbor ofa table saw relative to the guide groove in the supporting table of thetable saw and shown applied to the back arbor supporting trunnion of thetable saw;

FIG. 14 is a top plan view of the arbor aligning apparatus of FIG. 13;

FIG. 15 is an end view of the arbor aligning apparatus, looking in thedirection of arrow XV of FIG. 14;

FIG. 16 is a perspective view of a workpiece locating gauge whichembodies a self-adjusting accessory principle of the present inventionand shown applied to the supporting table of a conventional table saw;

FIG. 17 is a top plan view of the workpiece locating gauge; and

FIG. 18 is an end view of the workpiece locating gauge, looking in thedirection of arrow XVIII of FIG. 17.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring first to FIGS. 1-4 there is shown a self-adjusting accessorywhich is generally indicated by the reference numeral 21 and shownapplied to the supporting table of a conventional table saw which isgenerally indicated by the reference numeral 26. The table saw 26includes a workpiece supporting table which has an upper surface 30which contains a pair of guide grooves 31 and 32. The table saw 26 alsoincludes a ripping fence 34 which rests on the surface 30 and which isslidably mounted on a pair of guide rails 33. The ripping fence 34 canbe locked in any desired position on the supporting surface 30 by alocking mechanism, generally indicated by the reference numeral 35.

The self-adjusting accessory 21 includes a miter gauge 22 which ispivotally connected to a guide mechanism, generally indicated by thereference numeral 24, by means of a pivot pin 25. The guide mechanism 24includes an elongated bar 40 which contains a plurality of horizontalthreaded bores 48. Each of the bores 48 contains a moveable plungerwhich is generally indicated by the reference numeral 50. A screw 37 isfixed to one end of the bar 40 and extends upwardly through an arcuateslot 39 in the miter gauge 22. A locking nut 41 is threaded to the upperend of the screw 37 for locking the miter gauge 22 to the bar 40 in anydesired angle of position of the bar 40, relative to the miter gauge.

Referring particularly to FIG. 3, each horizontal bore 48 has a firstopening 47 in a first vertical side surface 44, and a second opening 49in the second vertical side surface 46. The bore 48 has internal threadswhich correspond to the external threads of a plug 51 which is threadedinto the bore 48 as shown in FIG. 3. The plug 51 has a chamber 52, afirst end wall 53 which is adjacent the opening 47, and a second endwall 55 which is adjacent the opening 49. The end wall 55 has a groove58 for receiving the blade of a screwdriver for rotating the plug 51 toselectively advance the plug 51 toward the opening 47 or to retract theplug 51 toward the opening 49. The first end wall 53 has an opening 54into the chamber 52. The plunger 50 has a relatively wide portion 62which is slidably mounted within the chamber 52 and a relatively narrowportion 60 which extends through the opening 54 in the wall 53 andthrough the opening 47 in the first vertical side surface 44. Acompression spring 56 is located within the chamber 52 for biasing therelatively wide portion 62 of the plunger against the first end wall 53so that the free end of the relatively narrow portion 60 of the plungerextends to an outer position beyond the first vertical side surface 44.The plunger 50 is movable axially against the bias of the spring 56 toan inner position wherein the outer end of the relatively narrow portion60 of the plunger is at least flush with the first vertical side surface44. The plug 51 functions as an adjustable stop mechanism for limitingthe outward extension of the free end of the plunger to determine theouter position of the free end of the plunger. The outer position of thefree end of the plunger can be changed by rotating the plug 51 withinthe bore 48. The plug 51, plunger 50 and spring 56 constitute ayieldable compensator, generally indicated by the reference numeral 61.

The miter gauge 22 is positioned on the work supporting table of thetable saw, as shown in FIG. 1, so that the guide bar 40 is slidablymounted within the guide groove 32. The free ends of the plunger 50 bearagainst the vertical side surface of the groove which is furthest fromand faces the cutting blade. The plungers 50 bias the second verticalside surface of the guide bar 40 against the vertical side surface ofthe groove 32 which is closest to and faces away from the cutting blade38. This insures that the vertical side surface 46 will always be flushwith the vertical side surface of the groove which faces away from thecutting blade 38 and which is closest to the cutting blade 38,regardless of how well the guide bar 40 fits within the groove 32 orwhether or not the guide groove 32 is uniform in width. If the operatorprefers to use the groove 31 on the opposite side of the cutting blade38, the plugs 51 are removed from the bores 48 and reinserted into thebores through the openings 47 so that the narrow portions 60 of theplungers extend through the openings 49. In this orientation, the firstvertical side surface 44 is biased flush against the vertical sidesurface of the groove 31 which faces away from and is closest to thecutting blade 38.

Referring particularly to FIG. 4, the guide bar 40 has a pair ofvertical threaded bores 64. An adjusting screw 66 is threaded into eachbore 64 from the top so that the lower end of the screw extends belowthe bottom surface 42 of the guide bar 40. The upper end of the screw 66has a hex socket 68 for receiving an alien wrench for adjusting thevertical position of the adjusting screw 66. The adjusting screw 66provides a vertical adjustment feature for the guide bar 40 to adapt theguide bar to the depth of the guide groove in the work supporting tableof the table saw. Guide groove depths vary considerably betweendifferent makes of table saws. The height of the guide bar 40 isadjusted so that the top of the guide bar is flush with the top surfaceof the work supporting table and the fixture to which it is attachedsuch as the miter gauge 22 is flush with the upper surface of the worksupporting table. The primary purpose of the adjusting screws 66 is toprevent the guide bar 40 from rocking within the guide groove.

Referring to FIGS. 5-8, there is shown a self-adjusting accessory for atable saw which is generally indicated by the reference numeral 70. Thefixture of the accessory 70 is an alignment gauge which is generallyindicated by the reference numeral 72. The alignment gauge 72 includes adial gauge, generally indicated by the reference numeral 76, which ispivotally mounted on a horizontal cross bar 74 for pivoting movementabout a horizontal axis by means of a pivot pin 75. The cross bar 74 isconnected to a guide mechanism 71 which includes an elongated guide bar73 that extends transversely of the cross bar 74 as shown in FIG. 6. Theguide bar 73 is similar to the guide bar 24 which was describedpreviously. The guide bar 73 contains a plurality of threaded bores 48which contain the plungers 50 and plugs 51 which are illustrated in FIG.3. The elongated guide bar 73 also includes a plurality of verticalbores 64, each of which contains one adjusting screw 66 which is shownin FIG. 4 for vertically adjusting the guide bars 73 within the guidegroove of the work supporting table of the table saw. The bar 73 differsfrom the bar 24 in that it has a threaded vertical aperture at amidpoint of the bar for receiving a screw 96 for connecting the crossbar 74 to the guide bar 73. The upper surface of the guide bar 73 has ahorizontal slot 93 for receiving the lower end of the cross bar 74 tomaintain the guide bar 73 at a right angle to the cross bar 74. Thecross bar 74 has a plurality of vertical apertures 94. The screw 96extends freely through any one of the apertures 94 and is threaded intothe threaded aperture in the middle of the bar 73 to enable the crossbar 74 to be mounted on the guide bar 73 at a plurality of positionsalong the length of the cross bar 74. This enables the accessory 70 tobe used with different makes of table saws which vary in the location ofthe guide groove 80 relative to the cutting blade of the table saw. Thescrews 66 are adjusted so that the guide bar extends above the surfaceof the work supporting table and the bottom surface of the cross bar 74is flush with the top surface of the work supporting table. The dialgauge is a commercially available gauge such as a model number 605-4070manufactured by Enco Company. The dial gauge 76 includes a circularhousing 86, a dial face 88, a dial 90, and an elongated feeler rod 92which is slidably mounted into the housing for movement longitudinallyof the cross bar 74. The feeler rod 92 has a free end which extendsbeyond the end of the housing 86 and the cross bar 74.

The accessory 70 has multiple functions, including that of an alignmentgauge for verifying the alignment of the cutting blade of a table sawrelative to the guide groove in the work supporting table of the tablesaw or for verifying the flatness of the cutting blade. Referring toFIG. 5, the accessory 70 is employed as an alignment gauge bypositioning the guide bar 73 within the guide groove 80 of the uppersurface 79 of a work supporting table 78 which forms part of a tablesaw, generally indicated by the reference numeral 77. The worksupporting table 78 of the table saw 77 also includes a vertical slot 82through which a cutting blade 84 extends. The guide bar 73 is located inthe groove 80 so that the free end of the elongated feeler rod 92engages the face of the cutter blade 84 at a first point to obtain afirst reading of the dial 90. The guide bar 73 is then movedlongitudinally along the guide groove 80 so that the free end of thefeeler rod 92 engages a second point on the cutting blade 84 to obtain asecond reading of the dial 90. The second reading of the dial 90 is thencompared with the first reading for verification of the alignment orflatness of the cutting blade 84, relative to the guide groove 80. Theplungers 50 maintain the vertical side surface of the guide bar 73 whichis closest to the cutting blade 84 flush against the vertical sidesurface of the guide groove 80 which is also closest to the cuttingblade 84. This eliminates any errors in reading of the dial gauge whichcould be attributed to variations in the guide groove 80. The pivotalmounting of the alignment gauge 72 enables the dial gauge to be rotatedabout the pivot pin 75 to a plurality of positions between thehorizontal full line position shown in FIG. 7 to the dotted linevertical position shown in FIG. 7. The pivot pin 75 is threaded into thecross bar 74 and is provided with a socket 81 for receiving acorresponding tool for rotating the pin 75 for loosening or tighteningthe pin 75. This enables the gauge 72 to be adjusted relative to thecross bar 74 so that the free end of the feeler rod 92 engages the faceof the cutting blade 84 at a point very close to the top surface 79 ofthe work supporting table 78. This enables readings to be taken at twoseparate points on the face of the cutting blade 84 which areconsiderably further apart than would be possible along a horizontalline which is spaced substantially above the top surface 79 of the worksupporting table. This provides a more accurate reading since anyvariation in the alignment of the cutting blade relative to the guidegroove of the work supporting table is more likely to be detected whentaking measurements at two widely separated points as compared to takingmeasurements at two points which are closer together.

The accessory 70 of the present invention can also be utilized formeasuring the right angle alignment of the arbor of a drill pressrelative to the work supporting table of the drill press. This isaccomplished by positioning the cross bar 64 beneath the chuck of adrill press so that one of the apertures 94 is aligned with the apertureof the chuck and inserting a pin through the aperture of the cross barand into the chuck opening. The chuck is tightened to secure the bolt.The dial gauge 76 is repositioned to the dotted line position shown inFIG. 7. The chuck of the drill press is then lowered so that the freeend of the feeler rod 92 touches the top surface of the work supportingtable of the drill press to obtain a first reading. The cross bar 74 isthen rotated about the bolt which supports the cross bar and the chuckso that the free end of the feeler rod 92 engages a second point on awork supporting table of the drill press to obtain a second reading. Acomparison of the two readings of the gauge 76 verifies if the chuck isat a right angle to the work supporting surface of the drill press.

Referring to FIGS. 9-12, the alignment gauge accessory 70 is utilized inconjunction with other elements for carrying out a method of checkingfor all variables which contribute to errors in the alignment of thecutting blade relative to the guide groove of the table saw and forverifying the alignment of the cutting blade. The additional elements ofthe apparatus for alignment verification include a reference plate 98which has a flat reference surface 100 and a central aperture 99. Thesurface 100 has a plurality of radial reference lines 101 which areevenly spaced at a predetermined number of degrees, as for example,every 60° as shown in FIG. 12. The plate 98 is adapted to be fixed ontothe arbor 102 of the table saw and rests against the stop 104. Theverification apparatus also includes a cap 106 which has a cylindricalsocket 114 for receiving the free end of the arbor 102 as shown in FIG.9. The cap 106 is fixed to the free end of the arbor 102 by means of setscrews 110. A compression spring 108 is adapted to be mounted on thearbor 102 between the reference plate 98 and the cap 106 and,preferably, bears against a washer 109 which is located between thereference plate 98 and the spring 108. The side surface of the cap 106is provided with a plurality of facets 116. In the example shown inFIGS. 9 and 10, the side surface of the cap 106 has six evenly spacedfacets 116 and has the general appearance of a hex nut.

The procedure for verifying the alignment of the cutting blade of thetable saw relative to the guide groove of the table saw begins by firstremoving a plate 83 which contains the slot 82 for the cutting blade toexpose the larger slot 112 in the work supporting table 78 of the tablesaw.

The first procedure to be completed is the verification of thestraightness of the arbor 102. This is accomplished by removing thecutting blade 38 and applying the reference plate 98 onto the arbor 102so that it rests against the stop 104. The alignment guide 72 is thenpositioned on the work supporting table so that the cross bar 72 islocated within the guide groove 80 and the elongated rod 92 engages thereference surface 100 of the reference plate. The basic method forverifying the straightness of the arbor 102 comprises maintaining thereference plate 98 stationery while rotating the arbor 102 for onecomplete revolution while pausing at regular angular increments torecord readings from the dial gauge 76. Since the surface 100 isperfectly flat, the readings from the gauge 76 will be the same for allangular positions of the arbor 102 if the arbor is straight. A referenceplate which has a reference surface which is not perfectly flat can alsobe used, as long as the reference plate is maintained in a stationaryposition. If the arbor 102 is crooked, the reading from the gauge 76will be different. This procedure is facilitated by applying the washer109 against the surface 100 of the reference plate 98 and applying thecompression spring 108 onto the free end of the arbor 102. The cap 106is then applied to the free end of the arbor 102 so that it compressesthe spring 108. The cap 106 is fixed to the arbor by set screws 110.This provides a biasing force against the reference plate 98. The cap106 provides a means for rotating the arbor 102 and the facets 116 serveas reference points to assist the operator in taking gauge readings atregular segments of rotation of the arbor 102. In the example shownFIGS. 9 and 10 the hexagonal shape of the cap 106 serves as a guide forsix readings at 60° intervals.

When it is determined that the arbor 102 is straight, the next procedureis to verify the alignment of the arbor 102 relative to the guide groove80 of the work supporting table 78. This is accomplished by applying thereference plate 98 and the washer 109 onto the arbor 102 so that thereference plate rest against the stop 104 and the washer 109 restagainst the reference plate 98. The reference plate 98 is fixed to thearbor 102 by applying the same nut which is normally used to secure thecutting blade to the arbor so that it bears against the washer 109. Thealignment gauge 76 is applied to the work supporting table as describedabove for checking the straightness of the arbor. A reading is taken atthe front end of the reference plate and a reading is taken at the rearend of the reference plate. If the arbor 102 is at a right angle to theguide groove 80 within a vertical plane, the front and rear readingsfrom the gauge 76 will be the same. If the arbor 102 is not at a rightangle to the guide groove 80, the readings on the gauge 76 will differ,thereby indicating a misalignment of the arbor 102 relative to the guidegroove of the work supporting table.

If it is determined, by using the procedures described above, that thearbor 102 is straight and that it is at a right angle alignment with theguide groove 80 of the work supporting table, the last procedure is toverify the flatness of the cutting blade 38 which is being used on thetable saw. This verification procedure is accomplished by mounting thecutting blade 38 to the arbor 102 in the same manner as the mounting ofthe reference plate 100 as shown in FIG. 9. The arbor 102 is then raisedso that the cutting blade extends above the top surface 79 of the worksupporting table to a maximum degree. The flatness of the cutting blade38 is verified by drawing a plurality of radial lines 113 on the flatsurface of the cutting blade which faces the guide groove 80. The radiallines 113 are spaced at even angular increments, for example at 60°intervals. The arbor 102 is maintained stationary and the cutting blade38 is rotated for one revolution while pausing at every 60° of rotation,as guided by the reference lines 113, to take a reading from the dialgauge 76. If the cutting blade 38 is perfectly flat, all of the gaugereadings will be the same. If the cutting blade 38 is warped, then thereadings from the gauge 76 will be different. Once it has beendetermined that the arbor is straight and the cutting blade is flat, thealignment of the arbor 102 can be verified with the use of the alignmentgauge 72. The dial gauge 76 is pivoted relative to the cross bar 74 sothat the free end of the elongated rod 92 touches the face of thecutting blade 38 just above the upper surface 79 of the work supportingtable 78. A first reading is taking at a first point on the cuttingblade. The accessory 70 is then moved along the guide groove 80 so thata second reading can be taken at a second point the opposite end of theexposed portion of the cutting blade.

When it is discovered that the arbor 102 is misaligned relative to theguide groove 80 during an initial series of verification tests or at asubsequent time during use of a table saw, the arbor 102 is readjustedinto a proper right angle alignment relative to the guide groove by theapparatus which is shown in FIGS. 13-15. The mechanism for aligning thearbor of the table saw comprise a pair of L-shaped brackets, generallyindicated by the reference numeral 126, for use with a table saw inwhich the arbor is supported on a cradle which is, in turn, supportedbetween a pair of trunnions. A front trunnion is located at the front ofthe table saw and a back trunnion is located at the back of the tablesaw. The back trunnion which is illustrated in FIG. 13, is generallyindicated by the reference numeral 118 and includes a pair ofhorizontally extending flanges 120. Each flange 120 has an aperture 122which is vertically aligned with a threaded aperture 124 in the worksupporting table 78. A bolt 134 extends through the aperture 122 and isthreaded into the aperture 124 to secure the trunnion 118 to the worksupporting table 78. Each aperture 124 is wider than the bolt, at leastin the lateral dimension, to enable the back trunnion 118 to be movedlaterally relative to the work supporting table 78.

Each L-shaped bracket 126 comprises a vertical leg 128 which contains ahorizontal threaded aperture 136 and a horizontal leg 130 which containsan aperture 132. If it is determined that realignment of the arbor isrequired. A center bolt 137 is loosened, the bolt 137 extends freelythrough an oversize aperture in a flange 139 of the trunnion 118 and isthreaded into the supporting table 78. The bolts which hold the backtrunnion 118 to the work supporting table 78 are removed and an L-shapedbracket 126 is positioned beneath each of the flanges 120 so that theaperture 132 of each bracket is vertically aligned with the adjacentapertures 122 and 124. A bolt 134 which is slightly longer than theoriginal bolts which held the back trunnion is inserted into theapertures 132 and 122 and is then threaded into the aperture 124,sufficiently to support the cradle 118 but not tight enough to preventthe back trunnion from being shifted laterally. The aperture 122 issubstantially larger in diameter, at least in the lateral dimension,than the bolt 134 allow for lateral shifting of the back trunnion 118.Each L-shaped bracket 126 includes an adjusting screw 138 which isthreaded into the aperture 136. After it has been determined whichdirection the back trunnion 118 must be shifted in order to bring thearbor into alignment with the guide groove of the work supporting table,the set screw 138 on the L-shaped bracket 126, from which movement ofthe cradle 118 must occur to achieve correct alignment of the arbor, isadvanced toward the adjacent flange 120 until it engages the end of theflange. The adjusting screw 138 is then advanced an additional amount toshift the trunnion 118 relative to the L-shaped bracket 126 and to thework supporting table 78 until the arbor is at a right angle to theguide groove of the work supporting table. At this point, the adjustingscrew 138 of the opposite L-shaped bracket 126 is advanced until itengages the end of the adjacent flange 120. A locking nut 140 isthreaded onto each adjusting screw 138 between the head of the screw andthe outer surface of the vertical leg portion 128. When the backtrunnion 118 has been correctly positioned and each adjusting screw 138is in engagement with its respective flange 120, the center bolt 137 istightened. The lock nuts 140 are then advanced toward their respectivevertical leg portions 128 so that the set screws 138 will remain intheir set position and the trunnion 118 will be prevented from shiftinglaterally out of adjustment during subsequent operation of the tablesaw. The bolts 134 are tightened to fully secure the back trunnion 118to the work supporting table 78.

Referring to FIGS. 16-18, there is shown a third self-adjustingaccessory of the present invention which is generally indicated b y thereference numeral 142. The accessory 142 includes a stop gauge,generally indicated by the reference numeral 144, which is connected tothe bar 73 which is utilized with the alignment gauge 72 to form theaccessory 70. The stop gauge 144 includes a cross bar 146 which has aplurality of vertical apertures 148 which enable the cross bar 146 to bemounted within the slot 93 of the guide bar 73 at a plurality ofpositions along the length of the cross bar 146 by means of an allenscrew 150. One end of the cross bar 146 has a notch 152 and a horizontalaperture 153 which extends to the notch 152. A generally rectangularblock (or housing) 154 is located within the notch 152 and has ahorizontal threaded aperture 156 which is horizontally aligned with theaperture 153 of the cross bar 146. A screw 159 is threaded into theaperture 156 for securing the block 154 to the cross bar 146. The block154 also has a threaded horizontal aperture 158 which is at a rightangle to the aperture 153. The threaded shank portion 162 of anadjusting screw or rod, generally indicated by the reference numeral160, is threaded into the aperture 158. The adjusting screw 160 has ahead portion 164 which has a knurled outer surface to enable theadjusting screw to be manually adjusted by axial rotation of theadjusting screw within the threaded aperture 158. Alternatively, theblock 154 may include a threaded aperture 161 which intersects threadedaperture or bore 148, and a set screw 163 which is threaded intoaperture 161 for releasably locking the screw (or rod) 160 in anyadjusted position.

The stop gauge 144 is used as a locating tool for a workpiece to enablenarrow strips to be cut from a workpiece, particularly for strips whichare to narrow to be safely cut along the ripping fence of the table sawin a traditional manner. If the strips to be cut are too narrow, theyare difficult to push through the saw between the cutting blade and theripping fence.

The stop gauge 144 of the present application is utilized by placing theguide bar 73 in the guide groove 31 in the work supporting table 28 ofthe table saw 26 so that the free end of the adjusting screw 160 extendstoward the cutting blade 38. The screw 160 is adjusted so that thedistance between the free end of the adjusting screw and the flatsurface of the cutting blade is equal to the width of the strip which isto be cut from the workpiece. In contrast to the other fixtures whichare utilized with the elongated guide bar 73, the vertical side surfaceof the guide bar which is furthest from the cutting blade is maintainedsnugly against the vertical side surface of the guide groove 31 which isalso furthest to the cutting blade, due to the biasing action of theplungers 50. When the free end of the adjusting screw 160 has beenadjusted to its desired position, the workpiece, which is generallyindicated by the reference numeral 166, is positioned on the uppersurface 30 of the work supporting table 28 so that the side edge of theworkpiece engages the free end of the adjusting screw 160, as shown inFIG. 16. The ripping fence 34 is then adjusted along the upper surfaceof the table 28 until it engages the opposite side edge of the workpiece166. At this point, the ripping fence 34 is locked in position. Theworkpiece 166 is then pushed through the cutting blade 38, which resultsin the cutting of a strip from the workpiece of a desired width. Ifanother piece having the same width as the first piece is to be cut fromthe workpiece, the workpiece is repositioned against the free end of theadjusting screw 160. The fence 34 is readjusted to engage the oppositeside edge of the workpiece and is secured in this position as before.The workpiece 166 is advanced through the cutting blade 38 to produce asecond narrow strip which is identical to the first strip. Thisprocedure can be repeated to produce as many identical narrow strips asdesired. The self-adjusting accessory 142, which employs the stop gauge144, can be utilized with a cross cut fixture for cutting a plurality ofpieces of the same length from a long workpiece. The stop gauge 144 ispositioned so that the free end of the adjusting screw 160 is positionedfrom the cutting blade 38 at a distance which is equal to the length ofthe pieces to be cut. A long workpiece is positioned on the worksupporting table so that the end of the workpiece engages the end of theadjusting screw 160. The workpiece is then advanced through the saw 38.Subsequent equal length pieces can be cut from the workpiece byrepeating this procedure.

The cross bar 146 of the accessory 142 is nearly identical to the crossbar 74 of the accessory 72 so that the stop gauge 144 and the alignmentgauge 72 can be used interchangeably with either cross bar.

Clearly, minor changes may be made in the form and construction of thisinvention and in the embodiments of the process without departing fromthe material spirit of either. Therefore, it is not desired to confinethe invention to the exact forms shown herein and described but it isdesired to include all subject matter that properly comes within thescope claimed.

The invention having been thus described, what is claimed as new anddesired to secure by letters patent is:
 1. Verification apparatus forchecking the accuracy and alignment of the arbor and cutting blade of atable saw relative to the guide groove in the work supporting table of atable saw which extends transversely of the longitudinal axis of thearbor, wherein said guide groove has a bottom surface and a pair ofopposed side surfaces and said arbor has a free end and a stop which isspaced from said free end, said apparatus comprising: (a) a referenceplate which has a flat reference surface and an aperture for enablingthe reference plate to be mounted on the arbor of a table saw, saidreference surface having markings at predetermined angular intervalsrelative to the aperture of the reference plate; (b) a cap having a borefor enabling the cap to be mounted on the free end of an arbor of atable saw, said cap having visual indicator means located atpredetermined angular intervals relative to the arbor; (c) locking meansfor removably fixing said cap to the free end of the arbor; (d) acompression spring for mounting on the arbor between said cap and saidreference plate for biasing the reference plate against a stop on thearbor of a table saw; and (e) an alignment gauge apparatus comprising:(1) an elongated guide bar for slidable mounting in the groove of atable saw, said guide bar having a generally rectangular cross sectionwhich includes a bottom surface, a first vertical side surface and asecond vertical side surface which is opposite said first vertical sidesurface; (2) a cross bar which is mounted on said guide bar so that saidcross bar extends substantially transversely of said guide bar; and (3)a dial gauge which is mounted on one end of said cross bar, said dialgauge having a housing which contains a dial face, a dial and a feelerrod which is operatively connected to said dial, and which is slidablymounted on said housing for movement longitudinally of said cross bar,said feeler rod having a free end which extends beyond the end of saidcross bar to which said dial gauge is attached.
 2. Verificationapparatus as recited in claim 1, wherein said elongated guide barfurther comprises at least two yieldable compensators which protrudefrom the first vertical side surface for engaging one of the sidesurfaces of the guide groove of a saw table to maintain the secondvertical side surface snugly against the other of the side surfaces ofthe guide groove.
 3. Verification apparatus as recited in claim 1,wherein said cross bar is adjustably mounted on said guide bar foroccupying a plurality of positions along the longitudinal axis of thecross bar and said alignment gauge apparatus further comprises backingmeans for fixing said cross bar in any one of said plurality ofpositions.
 4. Verification apparatus as recited in claim 1, wherein saidcap has a regular polygonal outer surface which extends about thelongitudinal axis of said arbor, said regular polygonal outer surfacerepresenting said indicator means.
 5. Verification apparatus as recitedin claim 1, wherein said cap has at least one threaded aperture whichextends into the bore of said cap and said locking means is a set screwwhich is threaded into said aperture.
 6. An adapter for aligning thecutting blade supporting arbor of a table saw which has a worksupporting table, a front trunnion which is located beneath the frontend of the work supporting table, a rear trunnion which is locatedbeneath the back end of the work supporting table, and a cradle which issupported between the front and back trunnions, each of said trunnionshaving first and second flanges which extend laterally from oppositeends of the trunnion, said first flange having a vertical end surfacewhich faces said guide groove and a bottom surface, said second flangehaving a vertical end surface which faces away from said guide grooveand a bottom surface, each of said flanges having a vertical aperturewhich extends completely through the flange and is vertically alignedwith a threaded vertical aperture in the bottom side of the worksupporting table for receiving a bolt which extends through the verticalaperture in the adjacent flange for securing the trunnions to the worksupporting table, the aperture in each of the flanges of at least one ofsaid trunnions being larger than the bolt, at least in the lateraldimension, said adapter being applicable to one of the trunnions uponremoval of the bolts which support said one trunnion, said adaptercomprising: (a) a first L-shaped bracket having a horizontal leg portionwhich has a vertical hole and a vertical leg portion which has athreaded horizontal hole that extends completely through the verticalleg portion, said horizontal leg portion being adapted to be ispositioned against the bottom surface of the first flange so that thevertical hole is vertically aligned with the vertical aperture of thefirst flange for enabling a bolt to be threaded into the threadedaperture of the work supporting table to secure the first L-shapedbracket and the first flange to the work supporting table; (b) a secondL-shaped bracket which is identical to said first L-shaped bracket, thehorizontal leg portion of the second L-shaped bracket being adapted tobe positioned against the bottom surface of the second flange so thatthe vertical hole of the second flange is vertically aligned with thevertical aperture of the second flange for enabling a bolt to bethreaded into the threaded aperture of the work supporting table tosecure the second L-shaped bracket and the second flange to the worksupporting table; (c) a first adjusting screw which extends completelythrough the horizontal hole in the vertical leg portion of said firstL-shaped bracket for axial movement toward and away from the verticalend surface of the first flange when the first L-shaped bracket isapplied to the first flange so that axial movement of said firstadjusting screw toward the first flange causes the trunnion to, movelaterally toward the second L-shaped bracket; and (d) a second adjustingscrew which extends completely through the horizontal hole in thevertical leg portion of said second L-shaped bracket for axial movementto ward and a way from the vertical end surface of the second flangewhen the second L-shaped bracket is applied to the second flange so thataxial movement of said first adjusting screw against the vertical endsurface of the second flange causes the trunnion to move laterallytoward the first L-shaped bracket so that the trunnion can beselectively moved laterally toward and a way from the guide groove. 7.An adapter for aligning the cutting blade supporting arbor of a tablesaw which has a work supporting table, a front trunnion which is locatedbeneath the front end of the work supporting table, a rear trunnionwhich is located beneath the back end of the work supporting table, anda cradle which is supported between the front and back trunnions, eachof said trunnions having first and second flanges which extend laterallyfrom opposite ends of the trunnion, said first flange having a verticalend surface which faces said guide groove and a bottom surface, saidsecond flange having a vertical end surface which faces away from saidguide groove and a bottom surface, each of said flanges having avertical aperture which extends completely through the flange and isvertically aligned with a threaded vertical aperture in the bottom sideof the work supporting table for receiving a bolt which extends throughthe vertical aperture in the adjacent flange for securing the trunnionsto the work supporting table, the aperture in each of the flanges of atleast one of said trunnions being larger than the bolt, at least in thelateral dimension, said adapter being applicable to one of the trunnionsupon removal of one of said bolts and the loosening of the other of saidbolts which support said one trunnion, said adapter comprising: (a) anL-shaped bracket having a horizontal leg portion which has a verticalhole and a vertical leg portion which has a threaded horizontal holewhich extends completely through the vertical leg portion saidhorizontal leg portion being adapted to be positioned against the bottomsurface of either one of the trunnion flanges from which a bolt has beenremoved so that the vertical hole is vertically aligned with thevertical aperture of said one trunnion flange; (b) a bolt for threadinginto the threaded aperture of the work supporting table to secure theL-shaped bracket and the trunnion flange to the work supporting table;and (c) an adjusting screw which extends completely through thehorizontal hole in said vertical leg portion for axial movement towardand away from the vertical end surface of said one trunnion flange whenthe L-shaped bracket is applied to said one trunnion flange so thatmovement of said adjusting screw against the vertical end surface ofsaid one trunnion flange the causes the trunnion to move laterally awayfrom the L-shaped bracket so that the trunnion can be selectively movedlaterally toward and away from the guide groove.
 8. A method of aligningthe cutting blade supporting arbor of a table saw which has a worksupporting table, a front trunnion which is located beneath the frontend of the work supporting table, a rear trunnion which is locatedbeneath the back end of the work supporting table, and a cradle which issupported between the front and back trunnions, each of said trunnionshaving first and second flanges which extend laterally from oppositeends of the trunnion, said first flange having a vertical end surfacewhich faces said guide groove and a bottom surface, said second flangehaving a vertical end surface which faces away from said guide grooveand a bottom surface, each of said flanges having a vertical aperturewhich extends completely through the flange and is vertically alignedwith a threaded vertical aperture in the bottom side of the worksupporting table for receiving a bolt which extends through the verticalaperture in the adjacent flange for securing the trunnions to the worksupporting table, the aperture in each of the flanges of at least theback trunnion being larger than the bolt, at least in the lateraldimension, said method comprising the following steps: (a) determining,with the use of an alignment gauge, the direction in which one of theback trunnion must be moved relative to the guide groove in order torender the arbor at a right angle to the guide groove; (b) loosening thebolt in the flange of the back trunnion toward which the back trunnionmust be moved in order to render the arbor at a right angle to the guidegroove; (c) removing the bolt from the other flange of the backtrunnion; (d) providing an L-shaped bracket having a horizontal legportion which has a vertical hole and a vertical leg portion which has athreaded horizontal hole which extends completely through the verticalleg portion; (e) positioning the horizontal leg portion of the L-shapedbracket against the bottom surface of the flange of the back trunnionfrom which a bolt has been removed so that the vertical hole isvertically aligned with the vertical aperture of the flange to which thebracket has been applied; (f) inserting a bolt through the vertical holein the leg portion of the L-shaped bracket and the vertical aperture ofthe adjacent flange and threading the bolt into the threaded aperture ofthe work supporting table sufficiently to support the L-shaped bracketand the trunnion flange to the work supporting table and to enable theback trunnion to be moved laterally; (g) threading an adjusting screwinto the horizontal hole in the vertical leg portion of the L-shapedbracket and advancing the adjusting screw until it engages the verticalend surface of the adjacent flange and moves the back trunnion adistance which aligns the arbor at a right angle to the guide groove ofthe work supporting table; and (h) tightening the bolts in both flangesof the back trunnion.
 9. A method of aligning the cutting bladesupporting arbor of a table saw as recited in claim 8, furthercomprising the following steps: (a) prior to step (g) of claim 8,removing the bolt in the flange of the back trunnion toward which backtrunnion is moved; (b) positioning the horizontal leg portion of asecond L-shaped bracket such as that which is described in step (d) ofclaim 8 against the bottom surface of the trunnion flange toward whichthe back trunnion is to be moved so that the vertical hole of saidsecond L-shaped bracket is vertically aligned with the vertical apertureof the flange of the back trunnion with which the second L-shapedbracket is engaged; (c) inserting a bolt through the vertical hole inthe leg portion of the second L-shaped bracket and the vertical apertureof the adjacent flange and threading the bolt into the threaded apertureof the work supporting table sufficiently to support the second L-shapedbracket and the adjacent trunnion flange to the work supporting tableand to allow the back trunnion to be moved laterally; (d) threading asecond adjusting screw into the horizontal hole in the vertical legportion of the second L-shaped bracket; (e) advancing the secondadjusting screw toward the vertical end surface of the adjacent flangeuntil the second adjusting screw engages the end surface of the adjacentflange after the back trunnion has been moved so that the arbor is at aright angle to the guide groove in the work supporting table; and (f)tightening the bolts in both flanges of the back trunnions.